This program of research concerns the chemistry of food-borne environmental toxicants; characterization of their mutagenicity to Salmonella typhimurium and to human lymphoblasts and their carcinogenicity to rodents; and experiments relating to their metabolism, interactions with cellular macromolecules, and mechanisms of action. Projects relating to chemistry involve studies of formation and detection of N-nitroso compounds and hydroxamates; products of pyrolysis of amino acids, proteins and other food materials; and reaction products of peroxidizing lipids and cholesterol oxidation. Metabolism of quercetin and other flavonols as well as amino acid pyrolysis products will be studied. Experiments on mode of action include isolation and identification of DNA adducts; quantitative and kinetic features of their levels in relation to mutagenesis and carcinogenesis; synthesis of DNA fragments containing adducts and their involvement in mutational events; effects of DNA damaging agents of the structure of E. coli DNA; and effects of chemical-macro molecular interactions on nucleolar structure and function in rat liver nuclei. Further studies are designed to determine the influence of diet composition on carcinogenicity of amino acid pyrolysis products; and detection of DNA damage caused by carcinogens in tissues of rats.